Determination of Viscoelastic Properties of Minor Concentrations of Zein Solutions With Dynamic Light Scattering (DLS) Microrheology

Abstract

In the present study, it was aimed to determi- nate the rheological properties of zein solutions using DLS microrheology. For this purpose, zein solutions at different concentrations range between 0,08 and 0,32% were produced in aqueous ethanol and optimized. Rheological properties, namely G' (storage modulus), G'' (loss modulus), G* (com- plex modulus), rı* (complex viscosity) and tan ö values, were determined. Regarding results of rheo- logical measurements, both G' and G'' values were found to the highest at 0,08% zein sample. Except 0,16% zein, there was a crossover point between G' and G'' values of the other samples. Complex vis- cosity nonlinearly decreased at all angular velocity values analyzed. Additionally, K' values of 0,08% zein sample were found to higher than those of 0,32 and 0,16% zein samples. No significant differences was observed between n', K'' and n* values of all samples. The findings indicated that DLS micro- rheology could be used for the measurements of rheological properties of small amount-zein solu- tions.